Muscle synergy and kinematic synergy analyses during sit-to-stand motions in hallux valgus patients before and after treatment with Kinesio taping.

OBJECTIVES: To explore the impact of hallux valgus (HV) on lower limb neuromuscular control strategies during the sit-to-stand (STS) movement, and to evaluate the effects of Kinesio taping (KT) intervention on these control strategies in HV patients. METHODS: We included 14 young healthy controls (HY), 13 patients in the HV group (HV), and 11 patients in the HV group (HVI) who underwent a Kinesio taping (KT) intervention during sit-to-stand (STS) motions. We extracted muscle and kinematic synergies from EMG and motion capture data using non-negative matrix factorization (NNMF). In addition, we calculated the center of pressure (COP) and ground reaction forces (GRF) to assess balance performance. RESULTS: There were no significant differences in the numbers of muscle and kinematic synergies between groups. In the HV group, knee flexors and ankle plantar flexors were abnormally activated, and muscle synergy D was differentiated. Muscle synergy D was not differentiated in the HVI group. CONCLUSION: Abnormal activation of knee flexors and plantar flexors led to the differentiation of module D in HV patients, which can be used as an indicator of the progress of HV rehabilitation. KT intervention improved motor control mechanisms in HV patients.

Pin fixation is an effective method for fixation of bunion osteotomy with various procedures: a retrospective cohort study.

BACKGROUND: Various fixation devices are available for bunion osteotomy. In this study, we evaluated the radiographic outcomes, postoperative complications, and recurrence rate in a series of hallux valgus deformities treated with various osteotomy procedures using a pin for the fixation of the osteotomy. METHODS: Two-hundred forty-seven patients with hallux valgus deformity managed with a Simple, Effective, Rapid and Inexpensive (SERI) osteotomy, distal chevron osteotomy, or proximal crescentic osteotomy and K-wire fixation were included. The mean follow-up of the patients was 53.9 ± 8.9 months. Radiographic evaluations included the assessment of the Hallux valgus angle (HVA), intermetatarsal angle (IMA), and union. Clinical evaluations included the assessment of the range of motion, pain in the first metatarsophalangeal joint, and patient satisfaction. RESULTS: In the last visit, the mean improvement of HVA was 23.9 ± 9.1º (P < 0.001). The mean IMA improvement was 6.1 ± 6º (P < 0.001). The mean metatarsophalangeal flexion and extension were 33 ± 10.7º and 34.6 ± 9.2º, respectively. Postoperative complications included pin tract infection in eight (3.2%) patients, deep infection in five (2%) patients, and early pin complication in four (1.6%) patients. Recurrence was observed in five (2%) patients. Twenty-three (9.3%) patients had slight pain in the last follow-up. The mean surgical time was smaller in the SERI osteotomy (P < 0.001). The mean hospitalization period was longer in the proximal osteotomy group (P = 0.039). The mean metatarsophalangeal flexion and extension were significantly smaller in the distal chevron osteotomy (P = 0.046 and P = 0.037, respectively). 90% of patients were satisfied or very satisfied with the surgical outcomes. CONCLUSION: K-wire fixation is a safe and effective device for the fixation of bunion osteotomy, and this effectiveness is even higher with SERI and proximal crescentic osteotomy.

Cross-sectional study of the prevalence of hyperextension of the first metatarsophalangeal joint and its relationship to onycholysis in women with hallux valgus.

BACKGROUND: Hallux Valgus (HV) deformity is associated with misalignment in the sagittal plane that affects the first toe. However, the repercussions of the first toe hyperextension in HV have been scarcely considered. The purpose of this study was to provide evidence of the association between first-toe hyperextension and the risk of first toenail onycholysis in HV. METHODS: A total of 248 HV from 129 females were included. The extension of 1st MTP joint was measured while the patient was in the neutral position of the hallux using a two-branch goniometer. The classification of the HV severity stage was determined by the Manchester visual scale, and the height of the first toe in the standing position was measured using a digital meter. An interview and clinical examination were performed to collect information on the presence of onycholysis of the first toe. RESULTS: Of the 248 HV studied, 100 (40.3%) had onycholysis. A neutral extension > 30 degrees was noted in 110 (44.3%) HV. The incidence of onycholysis was higher in HV type C than in type B (p = 0.044). The probability of suffering onycholysis in the right foot was 2.3 times greater when the neutral position was higher than 30 degrees (OR = 2.3; p = 0.004). However, this was not observed in the left foot (p = 0.171). Onycholysis was more frequent in HV with more than 2 cm height of the first toe (p < 0.001). For both feet, the probability of suffering onycholysis was greater for each unit increase in hallux height (right foot OR = 9.0402, p = 0.005; left foot OR = 7.6633, p = 0.010). CONCLUSIONS: The incidence of onycholysis appears to be significantly associated with HV showing more than 30º extension, and more than 2 cm height of the first toe. Height and hyperextension of the first toe together with first toenail pathology should be mandatory in the evaluation of HV.

Comparative effects of modified rotary scarf osteotomy and traditional scarf osteotomy in treating moderate to severe hallux valgus: a retrospective cohort study.

BACKGROUND: Traditional Scarf osteotomy (TSO) is an effective procedure with a good record in moderate to severe hallux valgus (MSHV) surgery. In order to overcome shortcomings of TSO, Modified Rotary Scarf osteotomy (MRSO) was introduced in this study, which aimed to compare the clinical and radiological outcome in the patients treated with MRSO or TSO. METHODS: Of 175 patients (247 feet) with MSHV, 100 patients (138 feet) treated with MRSO and 75 patients (109 feet) treated with TSO were evaluated according to relevant indicators in twenty-four months follow-up. Pre-surgical and post-surgical HVA, IMA, DMAA, MTP-1 ROM, sesamoid grade and AOFAS (American Orthopaedic Foot and Ankle Society) scores and postsurgical complications were evaluated. RESULTS: Both groups manifested similar baseline characters. The mean follow-up was of 25.9 (range, 22-37) months. Significantly lower IMA, lower Sesamoid grade and higher DMAA at six months, twelve months and twenty-four months post-surgically had been showed in MRSO group compared to TSO group. There was no significant difference in HVA, MTP-1 ROM and AOFAS data at each follow-up time point post-surgically between the two groups. No major complications occurred in either group. CONCLUSION: MRSO showed comparable results to TSO, and improved IMA and sesamoid grade to a greater extent, with a lower probability of throughing effect. Although DMAA could be increased by MRSO, MRSO could still be a reproducible, non-dangerous and efficacious alternative procedure for treating HV patients which do not have severe DMAA.

Eligibility for knee arthroplasty is associated with increased risk of acquired hallux valgus - a Mendelian randomized study.

OBJECTIVE: Clinically, it has been found that patients undergoing knee replacement have a high incidence of concomitant hallux valgus. In this study, we analyzed whether patients with osteoarthritis who underwent surgery and those patient who did not have surgery had an increased risk of hallux valgus by Mendelian randomization and performed reverse causal analysis. DESIGN: Genomewide association study (GWAS) data for osteoarthritis, categorized by knee arthritis with joint replacement, knee arthritis without joint replacement, hip arthritis with joint replacement, and hip arthritis without joint replacement.And acquired hallux valgus were downloaded for Mendelian randomized studies. MR analysis was performed using inverse variance-weighted (IVW), weighted median, and MR-Egger methods. MR-egger regression, MR pleiotropic residuals and outliers (MR-presso), and Cochran's Q statistical methods were used to evaluate heterogeneity and pleiotropy. RESULTS: The IVW results indicate that, compared to healthy individuals, patients who meet the criteria for knee osteoarthritis joint replacement surgery have a significantly higher risk of acquired hallux valgus. There were no significant causal relationships found for the remaining results. No significant heterogeneity or multiplicity was observed in all the Mr analyses. CONCLUSION: Our study supports the increased risk of acquired hallux valgus in patients eligible for knee replacement. There is necessary for clinicians to be concerned about the hallux valgus status of patients undergoing knee arthroplasty.

Automatic estimation of hallux valgus angle using deep neural network with axis-based annotation.

OBJECTIVES: We developed the deep neural network (DNN) model to automatically measure hallux valgus angle (HVA) and intermetatarsal angle (IMA) on foot radiographs. The objective is to assess the accuracy of the model by comparing to the manual measurement of foot and ankle surgeons. MATERIALS AND METHODS: A DNN was developed to predict the bone axes of the first proximal phalanx and all metatarsals from the first to the fifth in foot radiographs. The dataset used for model development consisted of 1798 radiographs collected from a population-based cohort and patients at our foot and ankle clinic. The retrospective validation cohort comprised of 92 radiographs obtained from 92 consecutive patients visiting our foot and ankle clinic. The mean absolute error (MAE) between automatic measurements by the model and the median of manual measurements by three foot and ankle surgeons was compared to 3° using one-tailed t-test and was also compared to the inter-rater difference in manual measurements among the three surgeons using two-tailed paired t-test. RESULTS: The MAE for HVA was 1.3° (upper limit of 95% CI 1.6°), and this was significantly smaller than the inter-rater difference of 2.0 ± 0.2° among the surgeons, demonstrating the superior accuracy of the model. In contrast, the MAE for IMA was 0.8° (upper limit of 95% CI 1.0°) that showed no significant difference from the inter-rater difference of 1.0 ± 0.1° among the surgeons. CONCLUSION: Our model demonstrated the ability to measure the HVA and IMA with an accuracy comparable to that of specialists.

Relationship between the medial cuneiform bone morphology and the severity of hallux valgus.

BACKGROUND: It has been reported on the relationship between the medial cuneiform bone morphology, especially in terms of obliquity, and the severity of hallux valgus (HV), however, no consensus has been obtained. On the other hand, there are no reports on the relationship between the difference in height between the medial and intermediate cuneiforms and the severity of hallux valgus. The purpose of this study was to clarify the relationship between the medial cuneiform bone morphology and the severity of HV. METHODS: The authors retrospectively analyzed 200 feet of 116 patients who had a weightbearing anteroposterior foot radiograph taken between April 2017 and July 2022 and diagnosed with HV. Measurements included the hallux valgus angle (HVA), the intermetatarsal angle (IMA), the distal medial cuneiform angle (DMCA) and the cuneiform first-second length (C1-2D). HV groups were classified into one of three groups: mild (15 ≦ HVA<30°, 9 < IMA<13°), moderate (30 ≦ HVA<40°, 13 ≦ IMA≦20°) and severe groups (HVA≧40°, IMA>20°), and the relationship to DMCA or the difference in height between the medial and intermediate cuneiforms was analyzed. RESULTS: A total of 163 feet of 93 patients were included in this study. There were significant correlations between the HVA and the DMCA (r = 0.47, p <0.001) or the C1-2D (r = 0.64, p <0.001). There was no significant difference in DMCA between the mild and moderate groups (p = 0.14). On the other hand, significant differences in C1-2D were observed between the three groups (mild-moderate; p <0.001, moderate-severe; p = 0.03, mild-severe; p <0.001). IMA was also positively correlated with the DMCA (r = 0.30, p <0.001) or the C1-2D (r = 0.47, p <0.001). However, the DMCA (p = 0.07) and the C1-2D (p = 0.39) did not differ significantly from IMA between the moderate and severe groups. CONCLUSIONS: The difference in height between the medial and intermediate cuneiforms, referred to as C1-2D, is closely associated with the HVA. The C1-2D may influence the progression of HV and be a novel radiographic parameter that indicates severity of HV.

First ray mobility in hallux rigidus, hallux valgus, and normal feet based on weightbearing computed tomography and three-dimensional analysis: A case-control study.

BACKGROUND: Hallux valgus and hallux rigidus are disorders affecting the first ray and are associated with hypermobility of this structure. This study aimed to investigate the three-dimensional mobility of each joint of the first ray between feet with hallux valgus or hallux rigidus and healthy feet using weightbearing and nonweightbearing computed tomography (CT). METHODS: This case-control study analyzed 17 feet of 11 healthy volunteers (control group), 16 feet of 16 patients with hallux valgus (HV group), and 16 feet of 11 patients with hallux rigidus (HR group). First, nonweightbearing foot CT imaging was performed in the supine position on a loading device with no load applied, with the legs extended and the ankle in the neutral position. Next, a load equivalent to body weight was applied for weightbearing CT imaging. Distal bone displacement relative to the proximal bone was quantified three-dimensionally under both conditions. RESULTS: In the HV group, the talonavicular joint showed significantly greater eversion (P = 00.011) compared with the control group and significantly greater dorsiflexion (P = 00.027) and eversion (P < 00.01) compared with the HR group. In the medial cuneiform joint, the HV group showed significantly greater eversion (P < 00.01) and abduction (P = 00.011) than the control group. For the first tarsometatarsal joint, the HV group showed significantly greater dorsiflexion (P = 00.014), inversion (P = 00.028), and adduction (P < 00.01) than the control group, and greater inversion (P < 00.01) and adduction (P < 00.01) than the HR group. Dorsiflexion of the first tarsometatarsal joint was significantly greater in the HR group compared with the control group (P = 00.026). CONCLUSION: Hypermobility of the first ray appears to be three-dimensional: in hallux valgus, it is centered at the first tarsometatarsal joint, while in hallux rigidus it is mainly in the sagittal plane at the first tarsometatarsal joint only. This difference may explain the different deformities ultimately observed in each condition.

Medial sesamoid position in moderate to severe hallux valgus: Correlation between three radiographic measurements.

BACKGROUND: In hallux valgus surgery, it is essential to accurately assess the position of the sesamoids both pre- and postoperatively. Weight-bearing foot anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views are radiographic methods used to assess the medial sesamoid position. This study aimed to measure the medial sesamoid position and evaluate the correlation between these three radiographic methods. METHODS: This retrospective study comprised 59 feet from 49 patients who underwent hallux valgus surgery. The mean age of patients was 54.6 (range, 22-70) years. We took preoperative and postoperative measurements using the weight-bearing anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views to assess the medial sesamoid position. RESULTS: The mean grades of the medial sesamoid position preoperatively and 6 months postoperatively were 2.5 and 0.8, 1.6 and 0.4, and 1.3 and 0.3 points based on the anteroposterior, tangential sesamoid, and computed tomography axial views, respectively (P < 0.001). Preoperatively, there was a strong positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.645) and anteroposterior and computed tomography axial views (P < 0.001, r = 0.468). In contrast, the tangential sesamoid and anteroposterior views showed a weak positive correlation (P = 0.03, r = 0.283). Six months postoperatively, there was a positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.473), anteroposterior and computed tomography axial views (P < 0.001, r = 0.470), and tangential sesamoid and anteroposterior views (P < 0.001, r = 0.480). CONCLUSIONS: We observed that the anteroposterior view exhibited a higher degree of medial sesamoid position displacement than the computed tomography axial and tangential sesamoid views. For the preoperative evaluation of the medial sesamoid position, the correlation between the computed tomography axial and tangential sesamoid views was stronger than that between the tangential sesamoid and anteroposterior views. However, all three views showed strong correlations postoperatively.

Relationship between first tarsometatarsal ligament morphology and its continuity with the fibularis longus and first tarsometatarsal joint degeneration.

This study explored the relationship between the morphological characteristics of the first tarsometatarsal ligaments and fibularis longus (FL) and the severity of articular cartilage degeneration in the first tarsometatarsal joint. Sixty legs from 30 cadavers were examined. The plantar, dorsal, and medial first tarsometatarsal ligaments were classified by fiber bundle number, and their morphological characteristics (fiber bundle length, width, thickness) were measured. The FL was categorized by its continuity with the plantar first tarsometatarsal ligament (PTML): Type A, connection with the PTML only on the first metatarsal; Type B, connection along the entire PTML; and Type C, no connection with the PTML. The severity of articular cartilage degeneration was assessed in four stages. No significant differences in cartilage degeneration among ligament types were found. Negative correlations were observed between the fiber bundle width and thickness of the PTML and the severity of cartilage degeneration. FL was classified as Type A in 68%, Type B in 27%, and Type C in 5% of feet. The fiber bundle thickness of the PTML in Type B was greater than in other types. Our findings suggest that smaller fiber bundle width and thickness in the PTML may be associated with severe cartilage degeneration. The FL had continuity with the PTML in 95% of feet and could enhance the mechanical strength of the PTML in Type B feet.

A comparison of three techniques for the osteosynthesis after minimal invasive osteotomies for hallux valgus.

PURPOSE: Third and fourth-generation minimal invasive osteotomies (MIO) for the treatment of hallux valgus (HV) have become popular procedures worldwide with promising results due to the improvement in the fixation method. The tricortical cannulated screw placement remains a complex procedure that is technically challenging and requires a long skill learning curve with high radiation exposure mainly in the form of intensifier shots (IS) required for the MIO fixation. This study aims to compare the number of X-ray IS required using three different techniques for the cannulated guide placement. METHODS: A retrospective cross-sectional observational and comparative study was conducted to assess the number of X-rays IS required for correct cannulated screw guide placement using three different techniques: traditional perforator, the drill and joystick, and K-wire first techniques. RESULTS: A total of 53 MIS procedures from thirty-one patients in two different hospitals were included. IS X-rays were 155.1 ± 29.7 in the traditional technique (n = 14), 143.0 ± 43.2 in the drill and joystick technique (n = 22), and 85 ± 18.7 in the K-wires first technique (n = 17), p = < 0.001 using one-way ANOVA. CONCLUSIONS: The K-wire first technique statistically significantly decreases X-ray IS numbers p ≤ 0.001. There were no statistically significant differences between the traditional (after osteotomy K-wire placement) and the drill and joystick techniques (p = 0.36).

Is there a tolerance for extension of the first metatarsal after the Lapidus procedure? A clinical, functional, and hindfoot radiographic analysis.

PURPOSE: Based on the tripod concept of load distribution, our study aimed to evaluate whether a slight extension of first metatarsal (M1) that may occur after the Lapidus procedure (LP) could alter the radiographic measurements of the hindfoot and influence clinical and functional outcomes. METHODS: Twenty-five patients (27 feet) were reviewed. Hindfoot radiographic analysis was based on seven measurements. Clinical and functional outcomes were evaluated with self-reported questionnaires. Transfer metatarsalgia was also assessed. Correlation analysis was performed according to variations of the studied variables. RESULTS: The average extension of the M1 was 4.26 degrees (p < 0.001). None of the hindfoot radiographic measurements changed significantly (p = 0.13, p = 0.50, p = 0.19, p = 0.70, p = 0.11, p = 0.36, p = 0.83). Patients improved on most questionnaires (p < 0.001). None presented transfer metatarsalgia. No correlation between M1 extension and clinical and functional outcomes was found. CONCLUSION: Possibly there is a tolerance of M1 extension in which it does not alter the radiographic measurements of the hindfoot, overload the lesser metatarsals, or compromise clinical and functional outcomes.

Rigid iatrogenic hallux varus: a decades' worth experience with arthrodesis of the metatarsophalangeal joint.

PURPOSE: Arthrodesis of the first ray metatarsophalangeal joint (MPJ) is the gold standard in iatrogenic hallux varus (IHV) in the presence of stiffness and osteoarthritis. The purpose of this study is to collect clinical and radiographic results and complications of MPJ arthrodesis in rigid iatrogenic HV. METHODS: A retrospective evaluation of rigid iatrogenic HV undergoing arthrodesis with a minimum follow-up (FU) of two years was performed. The clinical parameters assessed were visual analog scale (VAS), the AOFAS Hallux Metatarsophalangeal-Interphalangeal Scale score and the satisfaction scale. The radiological parameters evaluated the first to second metatarsal angle (IMA) and the angle of hallux valgus (HVA). Complications were also analysed. RESULT: A total of 18 patients (19 procedures) with a mean FU of 5.5 ± 2.5 years were included. The mean VAS improved from 7.3 ± 1.6 to 1.3 ± 1.2 (p < 0.05) at the last FU. Similarly, the AOFAS Hallux Metatarsophalangeal-Interphalangeal scale score significantly improved to 82 ± 9.2 (p < 0.05). Radiological evaluation demonstrated a 1-2 IMA improvement from 4.4 ± 2.2° preoperatively to 8.9 ± 2.4° at 3 months post-operatively. Similarly, there was a significant (p < 0.05) improvement of the HVA from - 22.7 ± 4.1° to 13.1 ± 4.1° at three months post-operative (p < 0.05). No signification loss of correction was noted at the last follow-up (p > 0.05). In one case, a delayed fusion at the arthrodesis site required surgical revision to promote fusion. No patient experienced pain with stress from the first MTP joint arthrodesis site or identified the arthrodesis site as a source of pain. No patient required implant removal. Re-operation and revision rates were 5.3%. The overall complications rate was 15.8%. CONCLUSIONS: MPJ fusion effectively corrects Iatrogenic Hallux Varus in cases of rigid and fixed deformities in the medium- to long-term follow-up, with lasting improvements in AOFAS and VAS scores. The procedure is characterised by a non-negligible risk of complications, reoperations and revisions. LEVEL OF EVIDENCE: Level IV, case series.

Percutaneous distal chevron osteotomy is associated with lower immediate postoperative pain and a greater range of motion than the open technique: A prospective randomized study.

PURPOSE: The results of past studies comparing percutaneous techniques with traditional open techniques for hallux valgus are controversial. Therefore, this study aimed to compare the radiologic and clinical outcomes of percutaneous and open distal chevron osteotomies. METHODS: Seventy-one patients with mild to severe hallux valgus deformity were randomized to undergo percutaneous distal chevron osteotomy (percutaneous group, n = 36) or open distal chevron osteotomy (open group, n = 35) between October 2019 and September 2020. Radiological and clinical outcomes were assessed preoperatively and postoperatively. Outcome measures included the foot and ankle outcome score, foot functional index, visual analogue scale (VAS) scores for pain, range of motion (ROM) of the first metatarsophalangeal (MTP) joint, hallux valgus angle, intermetatarsal angle, and first metatarsal shortening. Additionally, the first metatarsal declination angle was measured to evaluate sagittal malunion. RESULTS: The mean first metatarsal declination angle decreased significantly at 12 months postoperatively in both groups (p = 0.021 and p < 0.001 in the percutaneous and open groups, respectively), and the decrement was significantly greater in the open group (p = 0.033). The mean VAS score for pain on postoperative day one was 4.2 ± 1.9 and 5.3 ± 1.7 in the percutaneous and open groups, respectively (p = 0.019). The mean ROM of the first MTP joint did not change significantly after surgery, from 72.5 ± 7.5 preoperatively to 71.0 ± 9.5 at 12 months postoperatively in the percutaneous group (p = 0.215); however, it decreased significantly from 70.6 ± 7.3 preoperatively to 63.4 ± 10.4 at 12 months postoperatively in the open group (p < 0.001). There were no significant differences between the groups regarding other clinical outcomes. CONCLUSION: The percutaneous group showed a lower immediate pain level at postoperative day 1 and better ROM of the first MTP joint at 12 months postoperatively.

Outcome comparison of minimally invasive proximal and distal chevron Akin osteotomies in patients with severe hallux valgus deformity: A randomized prospective study.

PURPOSE: To date, the surgical treatment of severe hallux valgus deformity remains challenging despite the various methods presented. This study aimed to compare the effectiveness of minimally invasive distal chevron Akin osteotomies (d-MICA) and minimally invasive proximal chevron Akin osteotomies (p-MICA) in correcting severe hallux valgus deformities. METHODS: This prospective follow-up study included patients randomly assigned to undergo p-MICA or d-MICA for hallux valgus deformities with a preoperative hallux valgus angle (HVA) ≥ 40° and/or a first to second intermetatarsal angle (IMA) ≥ 16°. After a minimum follow-up period of two years, we compared various clinico-radiographic parameters of patients whose HVA exceeded 15° at the final follow-up. RESULTS: In the p-MICA and d-MICA groups, seven of 40 cases (17.5%) and 16 of 41 cases (39.0%), respectively, exhibited HVA > 15° at the final follow-up (P = 0.048). The preoperative parameters showed no significant differences. However, at the first weight-bearing assessment, the HVA, IMA, and relative second metatarsal length were significantly smaller, and the distal metatarsal articular angle (DMAA) was greater in the p-MICA group (all P < 0.05) compared with the d-MICA group. Postoperatively, both groups exhibited significant decreases in HVA and IMA at the final follow-up (P < 0.001 for all parameters). The p-MICA group showed no significant changes in DMAA and the relative length of the second metatarsal (P = 0.253 and 0.185, respectively). However, the d-MICA group showed a significant decrease in DMAA (P < 0.001) and an increase in the relative length of the second metatarsal at the final follow-up (P = 0.01). CONCLUSIONS: p-MICA and d-MICA procedures demonstrated effective correction potential for severe hallux valgus deformities; however, the d-MICA procedure exhibited a notably higher incidence of unsatisfactory correction at the final follow-up than p-MICA. Therefore, d-MICA may be less predictable in achieving successful outcomes than p-MICA in treating severe hallux valgus deformities.

Classification of hallux valgus deformity-is there a standard?

INTRODUCTION: Hallux valgus deformity severity is one determent for the surgical procedure for hallux valgus (HV) correction. HV deformities are usually classified into mild/moderate/severe. The aim was to investigate the cut-off criteria used to classify HV deformity. MATERIALS AND METHODS: The study was based on a previous living systematic review. Four common databases were searched for the last decade. All review-steps were conducted by two reviewers. Data assessed were the individual cut-off values used to classify HV deformity into mild/moderate/severe, and the referenced classification systems. RESULTS: 46 studies were included. 21/18 studies grade deformity based on the intermetatarsal angle (IMA)/ hallux valgus angle (HVA) with great heterogeneity throughout the different cut-off values. The most referenced classification systems were the Coughlin and Mann's and the Robinson classification. CONCLUSIONS: The currently used classification systems are heterogenic, and no standard could be defined. The community should define a uniform classification system. LEVEL OF EVIDENCE: Level I, systematic review of randomized controlled trials and prospective comparative studies.

Correction potential and outcome of various surgical procedures for hallux valgus surgery: a living systematic review and meta-analysis.

INTRODUCTION: More than 100 surgical techniques are described for hallux valgus (HV) correction, but the most appropriate technique remains debatable. The aim of this study was to develop and conduct a "living systematic review" for the outcome of surgically treated HV. MATERIALS AND METHODS: The "living systematic review" was conducted per the PRISMA-P and PICOS guidelines and is the basis for the German AWMF S2e guideline "Hallux valgus" (033-018). Four common databases and the grey-literature were searched. Eligible were studies on adult patients comparing either two different primary surgical interventions or the same primary surgical intervention for different hallux valgus severities. The main outcome parameters were the osseous correction potential and the patient rated outcome. RESULTS: Out of 3022 studies, 46 studies (100 arms) were included. The meta-analysis included 31 studies (53 arms). The IMA (1933 procedures) improved on average by 7.3°, without significant group differences. The HVA (1883 procedures) improved on average by 18.9°, with significantly better results for third generation MIS (21.2°). The AOFAS (1338 procedures) improved on average by 33.8 points without significant group differences. The meta-regression revealed constant AOFAS scores over time. 69%/39% of the correction potential for the IMA/HVA could be explained by the preoperative values and 82% of the AOFAS improvement by the preoperative AOFAS scores. CONCLUSION: Open and minimally invasive techniques are powerful tools to correct hallux valgus deformity. Third generation MIS procedures revealed a possible superiority for the correction of the HVA. The AOFAS improvement appeared to be constant over time. LEVEL OF EVIDENCE: Level I; living systematic review and meta-analysis of prospective comparative studies (level II) and randomized controlled trials (level I).

Minimally invasive hallux valgus surgery using 3D printed patient specific instrumentation.

In this technical report study, we describe technique for performing the osteotomy and screw passage in minimally invasive fourth-generation hallux valgus surgery with transverse and akin extra-articular metaphyseal osteotomy (META) using a 3D-printed patient-specific surgical instrumentation guide. In an effort to minimize the learning curve and address the variability associated with technical corrections and screw placement, we have initiated the creation of personalized patient-specific instrumentation guides using 3D printing. Our hypothesis is that this approach will enhance safety, precision, decrease surgical time, and reduce exposure to radiation. Level of Evidence: Level V, expert opinion.

Patient-reported outcome measures in studies on hallux valgus surgery: what should be assessed.

INTRODUCTION: In recent years, there has been an increasing demand for patient-reported outcome measures (PROMs) to assess the outcome following orthopedic surgery. But, we are lacking a standard set of PROMs to assess the outcome of hallux valgus surgery. The aim of this study was to analyze the chosen patient rated outcome scores used in studies reporting on hallux valgus surgery. MATERIALS AND METHODS: The study was based on a previously published living systematic review. Included were prospective, comparative studies of different surgical procedures or the same procedure for different degrees of deformity. Four common databases were searched for the last decade. Study selection, data extraction, and risk of bias assessment were made by two independent reviewers. Data assessed were the individual PROMs used to assess the outcome of hallux valgus surgery. RESULTS: 46 studies (30 RCTs and 16 non-randomized prospective studies) met the inclusion criteria. The most commonly used clinical outcome measures were the AOFAS (55%) and the VAS (30%). No differences were found between frequency of the individual scores per the level of evidence or the type of osteotomy. CONCLUSION: Based on a systematic literature review, the AOFAS and VAS are the most frequently used outcome tools in studies assessing the outcome following hallux valgus surgery. Based on the literature available, the MOXFQ is a more valid alternative. LEVEL OF EVIDENCE: Level I; systematic review of prospective comparative (level II) and randomized controlled trials (level I).

The effect of hallux valgus on the anatomy of the nerves around the first metatarsal bone.

OBJECTIVE: To identify the variations in the location of the nerves that may be at risk in hallux valgus (HV) surgery, and to reveal whether these nerves are affected by the anatomical changes associated with HV. METHOD: In the formalin fixed, 46 lower extremities (19 female, 27 male) (9 normal, 14 mild HV, 21 moderate/severe HV), extensor hallucis longus tendon (EHL), deep plantar artery, medial dorsal cutaneous (MDCN), deep fibular (DFN), common plantar digital (CPDN) and proper plantar digital (PPDN) nerves were examined. The branches of MDCN extending to the medial side of foot were recorded in three segments. The positional topography of nerves according to EHL were analyzed on 360° circle and clock models. RESULTS: Sex-related differences observed in some parameters in direct measurements were not found in the clock model comparisons. In advanced HV angles (> 20°), DFN was closer to EHL in the distal part of the metatarsal bone, while there was no difference in the proximal. The intersection of the medial branch of the MDCN with the EHL was more proximal in HV cases than in normal feet. The location of the nerves in the clock pattern did not change in HV. Of the nerve branches reaching the medial side of the foot, 65.2% were in Part I, 71.7% in Part II, and 4.3% in Part III. CONCLUSION: Sex differences in the distance of the nerves to the EHL disappeared when the size effect of the cross-section of the first metatarsal bone region was eliminated with the clock model. Only in advanced HVA (>20°) (not in mild HV), the DFN being closer to the EHL distally and the intersection of the medial branch of the MDCN with the EHL in HV being more proximal than in normal can be interpreted as specific reflections of HV progress. The variations we revealed in the number of branches reaching the inside of the foot may explain the diversity of neuromas or nerve injuries associated with HV surgery.